[Mode B] Add logic to show Mode B rollback infobar

This is a one-time infobar notifying users they have been removed from
the 3PCD 1% experiment. It will persist in a tab after showing, but does
not require interaction to dismiss and will automatically dismiss when
the user switches tabs

Mock: https://screenshot.googleplex.com/yyySqMBQhpFtVjn

Bug: b:442876161
Change-Id: Icef1034945c112b4ec40269c0dba324505437f47
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6940602
Auto-Submit: Fiona Macintosh <fmacintosh@google.com>
Commit-Queue: Fiona Macintosh <fmacintosh@google.com>
Reviewed-by: Darryl James <dljames@chromium.org>
Reviewed-by: Abe Boujane <boujane@google.com>
Cr-Commit-Position: refs/heads/main@{#1516161}